DEMONSTRATION. Whatever is said or written to designate a thing or person. For example, a gift of so much money, with a fund particularly referred to for its payment, so that if the fund be not the testator's property at his death, the legacy will fail; this is called a demonstrative legacy. 4 Ves. 751; Lownd. Leg. 85; Swinb. 485.
2. A legacy given to James, who married my cousin, is demonstrative; these expressions present the idea of a demonstration; there are many James, but only one who married my cousin. Vide Ayl. Pand. 130; Dig. 12, 1, 6; Id. 35, 1, 34 Inst. 2, 20, 30.
3. By demonstration is also understood that proof which excludes all possibility of error; for example, mathematical deductions.